Physiology and Molecular Biology of Stress ... - KHAM PHA MOI

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Z . Dajic
This is also true for the highly tolerant wild relative of wheat, Lophopyrum
elongatum, whose chromosome arms 1ES, 7ES and 7EL were shown to play a role in
enhanced K + /Na + selectivity in wheat, according to studies using the amphiploid with
wheat cultivar Chinese Spring (Deal et al., 1999).
4.3. Ion Retranslocation, Allocation and Leaching
Retranslocation of ions via the phloem is a potentially important mechanism of
preventing salt accumulation in fully expanded leaves, while at the same time it represents
a threat to younger leaves, which are phloem sinks. It seems that cells of saltsensitive
plants lack Na + /H + transporters at the tonoplast, and therefore, cannot efficiently
sequester any excess of ions into the vacuoles (Jacoby, 1994). Instead, they
Figure 1. The Na: K ratio in leaf 4 of barley cultivars exposed to salinity
(1- cultivar Jelen, 2- NS 310, 3- NS 430, and 4- Viktor)
Figure 2. The Na: K ratio in leaf 3 of maize cultivars exposed to salinity
(1- cultivar B73, 2- DTP79, 3- Polj17, 4- F2)